Disposable absorbent articles, such as diapers, are used to collect and store bodily exudates such as urine and feces from wearers, such as babies. To prevent undesired leakage, absorbent articles should fit well against the wearer, and a number of measures have been adopted to provide good fit.
One such measure is the use of elastic side panels in diapers. These are panels which extend laterally from, for example, the rear of the diaper, and include fastening elements at their distal ends which attach to the front of the diaper, thus securing the diaper about the waist of the wearer. However, due to their elastic nature, the amount of extension which the elastic side panels undergo can vary. An elastic side panel which is not sufficiently tight will risk that the diaper is not secure about the wearer, causing it to slip out of place or fall off completely. In addition, loose diapers are susceptible to leakage. On the other hand, an elastic side panel which is stretched too tightly about the wearer's waist may cause discomfort and pain to the wearer, and may also risk distorting the diaper, causing poor fit and leakage. It is particularly important to ensure that elastic side panels in baby diapers are extended by the correct amount (i.e. with the correct force), as elastic side panels allow a small diaper to be stretched above its optimal level to fit a larger baby, when a larger diaper size may in fact be more appropriate.
It is known to provide indicia on elastic side panels which change shape upon extension of the side panel. When the appropriate extension has been reached, the indicia have a certain appearance. For example, WO 05/037159 shows an example in which a drawing of a cartoon rabbit is compressed laterally before the elastic side panel is stretched, but which becomes more rounded when a suitable degree of extension has been reached. A disadvantage with this solution is that it is rather subjective. What one person applying the diaper might consider a suitable shape for the indicia, may be different to what another person thinks. As such, the extension in the elastic side panel in WO 05/037159 can vary, depending on the user's perception of what the “correct” form of the indicia should be. In addition, the solution provided by WO 05/037159 gives no indication as to the correct placement of the elastic side panel on the front of the diaper (e.g. in the longitudinal direction of the diaper).
Another solution is provided by WO 01/21126. A first indicium element is located on the outermost edge of a side panel, while a second indicium element is located in the front waist region of the diaper. Closing the diaper correctly results in the first and second indicium elements forming an image which is a combination of the first and second indicium elements. For instance, the first indicium element is shown as a balloon, while the second is a teddy bear. Fastening the diaper correctly provides a combined image of a teddy bear holding the balloon. However, this solution does not require that the indicium element on the side panel changes shape upon stretching, so the diaper user does not have the clear impression of a changing degree of stretch.
U.S. Pat. No. 5,133,707 concerns an adhesive fastening tape for a diaper, which is transparent yet embossed to create indicia. Once the tape is applied to the diaper, the indicia on the tape will disappear against the colored landing zone.
US 2007/0049896 discloses an absorbent article having a size fit indicating means for indicating when the article is too large for a wearer. Two target strips for fasteners are provided on the front body panel and a visual sizing indicator is positioned between the two target strips, so that when the fasteners overlap the sizing indicator, it is an indication that the article is too large.
U.S. Pat. No. 5,897,546 discloses a diaper having a fastening system including tape fasteners and a target area in the form of a transparent receiving sheet intermittently bonded to the outer sheet of the front body panel by means of an adhesive serving as a positioning indicator for the tape fasteners.
U.S. Pat. No. 6,488,202 discloses a device and method for identifying a size of an absorbent article which is appropriate for a potential wearer based on at least two characteristics, such as weight and height.
WO 03/034966 discloses an absorbent article having fasteners in the form of hook material engageable with the outer nonwoven surface of the front body panel and wherein landing zone graphics are printed in the target area for the fasteners and covered by an outer nonwoven and visible through the outer nonwoven.
Co-pending PCT application PCT/SE07/000637 discloses an absorbent article having size fit indicating means which is hidden when the correct diaper size is used, but revealed when the diaper is too small.